<span style="color:#000080;font-weight:bold;">def </span><span style="color:#000000;">foo</span><span style="">(</span><span style="color:#000000;">a</span><span style="">: </span><span style="color:#000000;">Any</span><span style="">,</span> <span style="color:#000000;">b</span><span style="">: </span><span style="color:#000000;">Any</span><span style="">,</span> <span style="color:#000000;">/</span><span style="">,</span> <span style="color:#000000;">c</span><span style="">: </span><span style="color:#000000;">Any</span><span style="">,</span> <span style="color:#000000;">d</span><span style="">: </span><span style="color:#000000;">Any</span><span style="">)</span> -&gt; <span style="color:#000000;"><span style="color:#000080;font-weight:bold;">None</span></span>